Chapter 9: Dictionaries

Question 1

The algorithm used to implement Python dictionaries.

Answer 1

hash table

Question 1

A mapping from a set of keys to their corresponding values.
An associative lookup

Answer 1

dictionary

Question 2

A function used by a hash table to compute the location for a key.

Answer 2

hash function

Question 3

A set of counters

Answer 3

histogram

Question 4

A way of performing a computation.

Answer 4

implementation

Question 5

Another name for a key-value pair.

Answer 5

item

Question 6

An object that appears in a dictionary as the first part of a pair.

Answer 6

key

Question 7

The representation of the mapping from a key to a value.

Answer 7

key-value pair

Question 8

A dictionary operation that takes a key and finds the corresponding value.

Answer 8

lookup

Question 9

When there are one or more loops “inside” of another loop. The inner loop runs to completion each time the outer loop runs once.

Answer 9

nested loops

Question 10

An object that appears in a dictionary as the second part of a pair. This is more specific than our previous use of the word.

Answer 10

value

Question 11

function that creates a dictionary with no items

Answer 11

dict()

Question 12

dictionary notation

Answer 12

{key : value, etc}

Question 13

notation to add item to dictionary

Answer 13

dict_name[key] = value

Question 14

notation to print dictionary value

Answer 14

print(dict_name[key])

Question 15

KeyError

Answer 15

Error when key not in dictionary

Question 16

function that returns number of key-value pairs

Answer 16

len(dict_name)

Question 17

operator to determine if KEY is in dictionary

Answer 17

in
key in dict_name = True

Question 18

method to determine if value is in dictionary

Answer 18

.values()
vals = list(dict_name.values())
value in vals = True

Question 19

built-in function to convert a character to its integer equivalent

Answer 19

ord()

Question 20

way of performing a computation

Answer 20

implementation

Question 21

dictionary method that takes a key and default value. If the key is in the dictionary, it returns the value. Else, returns default value

Answer 21

.get()
dict_name.get(key, default value) = value or default value

Question 22

notation that returns a dictionary value

Answer 22

dict_name[key]

Question 23

This static method returns a translation table usable for str.translate().

If there is only one argument, Character keys will be converted to ordinals (integers).

If two arguments, in the resulting dictionary each character in x will be mapped to the character at the same position in y. If there is a third argument, it must be a string, whose characters will be mapped to None in the result.

Answer 23

str.maketrans(x[, y[, z]])

str.makestrans(fromstring, tostring, deletestring))

Question 24

string constant that specifies all the punctuation characters
need to import string module to use
no parentheses

Answer 24

string.punctuation

Question 25

returns a string that has been created
such that any and all characters in s have been removed, and the remaining characters are translated using table (being a 256 character string giving the translation by ordinal indexing). If table is None, then
the translation is not performed.

Answer 25

string.translate(s, table[, deletechars])